Influence of CSF/GF ratio on tribological behavior of hybrid fiber-reinforced braking friction materials

With the ever-expanding demand for friction materials, the environmental problems associated with their production and application have become increasingly prominent. This trend is attracting growing attention to develop green braking friction materials to replace traditional synthetic fiber-reinforced braking friction materials. In this study, five types of hybrid fiber-reinforced braking friction materials containing different corn stalk fiber (CSF) and glass fiber (GF) contents were prepared, and then the influence of the CSF/GF ratio on the thermal property, tribological properties and morphological performances was systematically investigated. The addition of more CSF and less GF could stabilize the friction coefficient and increase the wear resistance of the braking friction materials. Moreover, the worn surface was also evaluated using scanning electron microscopy. It could not only reveal the formation of contact plateaus on the friction surface after the addition of more CSF, but reveal the important transformation of the major wear mechanisms from adhesive and fatigue wear to abrasive wear. The sample with 2 wt% GF and 10 wt% CSF and the sample with 12 wt% CSF exhibited the best tribological properties and morphological performances under dry friction conditions.